Arbor attachment for lathes



June 14, 1938. HENWOOD 2,120,782

ARBOR ATTACHMENT .FOR LATHES Fi'led se t. 1, 1937 IHIII rm H P040 fi f/Vwooa,

INVENTOR.

A TT ORNE Y.

Patented June 14, 1938 UNITED STATES PATENT OFFICE ARBOR ATTACHMENT FOR, LATHES Harold Henwood, Centerville, Ind.

Application September 1, 1937, Serial No. 161,909

6 Claims.

My present invention relates to a device which is primarily to be used in connection with lathes for finishing or refinishing cases to which ring gears are secured in automobile differentials, and the principal object of the invention is the provision of a device for rigidly holding and maintaining the case in perfect alignment throughout the finishing process.

Another object of the invention is the provision of a device which is quickly adaptable to different sizes of differential cases with a minimum of changes being necessary in connection therewith.

Still another object of the invention is the provision of a device which automatically aligns the case for finishing the surface of a case to which the ring gear is to be secured.

A further object of the invention is the provision of a device which is simple of construction, which is universal in its adaptation to differential cases, and which may be economically manufactured.

Other objects and advantages of the invention will suggest themselves in the course of the following description, and that which is new will he pointed out in the appended claims.

The features of the invention will be hereinafter referred to in detail in the following description, reference thereto being had in the accompanying one sheet of drawings, in which:

Figure 1 is a side elevation .of the device showing the same secured in a lathe, and with a dif ferential case being secured therein.

Figure 2 is a detail longitudinal section through the device, with a differential case being shown dotted therein.

Figure 3 is an end elevation of the device taken from line 33 of Figure 2.

Figure 4 is a detail end elevation of the device and with the same being taken from line 44 of Figure 2.

Like characters designate like parts throughout the several views.

In order that the construction, the operation, the adaptation, and the advantages of the invention may be more fully understood and appreciated, I will now take up a detailed description thereof, in which I will set forth the same as fully and as comprehensively as I may.

Referring now to the drawing in detail, A designates the bed-plate of a lathe, B designates the sliding support of the lathe, C designates the face plate, and D designates the lathe spindles which hold the device in the lathe.

l designates the shaft which extends longitudinally of the device with the enlarged portion 2 being formed integrally with one end portion thereof. The opposite end of the shaft I has the external threads 3 formed thereon for the reception of the clamping nut 4. An aperture 5 is formed in each end of the shaft l with each of the apertures being located concentrically with relation to the periphery of the shaft at the respective end portions thereof.

The lever B is rigidly secured to the face portion of the member 2 by means of the threaded screws 1, the same being threaded into apertures which are formed in the member 2. The lever B provides a means for rotating the shaft l together with the case X. A lug E is rigidly secured to the face plate C and contacts the lever 6, thereby rotating the same simultaneously with the face plate.

A collar 1 is adapted to be slipped on the shaft l, with the threaded set screw 8 being threaded therethrough, and forming a means for rigidly securing the collar 1 on the shaft I. Apertures are formed through the differential cases, through one of which the set screw 8 extends, with the same contacting the differential case and causing the same to turn with the shaft I.

A collar member 9 is slidably positioned on the shaft I adjacent the member 2, and has the counterbore 9 formed therein to receive the bearing H), with a relief counterbore of a smaller diameter being provided for clearance of the hub portion of the differential cases. A second slidable collar member ll, having the counterbore ll formed therein, is provided at the opposite end of the shaft 1, and together with the bearing i2 is similar to the collar 9 and the bearing l0 respectively. A spacer collar I3 is provided to bear against the central portion of the collar II and is held tightly thereagainst by means of the clamping nut 4. It will be noted that the collar members 9 and I! also have the counterbores 9" and II" respectively formed therein for the reception of bearings, but that the counterbores 9" and H are of different diameters than the counterbores 9' and II, and thereby providing for the reception of bearings of different sizes, and subsequently for differential cases of different sizes. Each of the collars 9 and ii may be reversed on the shaft l in order to be adaptable to different sizes of differential cases. Also, a series of additional collars having various sizes of counterbores may be provided in order to adapt the same to extreme variations in the sizes of differential cases.

The purpose of the collars 9 and II together with the respective bearings I and I2 is to rigidly maintain the differential case X in clamped and concentric relation with the shaft I while the surface X is being finished with a cutting tool, and with the case being rotated by means of the face plate lug E, through the lever B, the end member 2, the shaft I, and the collar 1 together with the set screw 8.

In the assembly of the device together with a difierential case X, the collar member 9, having the bearing ill therein, is positioned on the shaft I and bears against the end member 2, as shown in Figure 2. The differential case X is then positioned on the shaft l with the hub thereof being inserted in the center of the bearing Ill. The collar 1 is next positioned on the 'shaft, and the set screw 8 is threaded through the collar 1 with the end of the set screw bearing against the shaft l. The portion X" of the differential case is then placed in position, as shown in Figures 1 and 2, after which the collar H together with the bearing l2 are positioned on the shaft with the hub portion of the differential case being extended into the bearing l 2, as shown in Figure 2. The spacing collar i3 is positioned on the shaft l, with one end thereof bearing against the central portion of the collar H, and with the clamping nut 4 being tightened against the opposite end of the spacing collar I 3. With the device thus assembled, the same is positioned in a turning lathe with the pointed ends of the spindles D being inserted in the apertures 5 of the shaft I. The entire device, together with the differential case, is rotated by means of the face plate lug E contacting the arm member 6. The surface X of the differential case is then accurately finished by means of the usual lathe cutting tool.

The device, as shown and described, has been thoroughly tested, and has been found to produce better results than other devices used for the specific purpose set forth, with the same producing cases finished to closer tolerances, and thereby making the finished and assembled cases more perfect.

I desire that it be understood that minor changes may be made in the several details and. in the arrangement of the parts herein shown and described, insofaras the changes may fall within the scope of the appended claims.

Having now fully shown and described themvention, what I claim, and desire to secure by Letters Patent of the United States, is

1. In an arbor attachment for lathes, a central shaft, a pair of spaced-apart collars slidably positioned on said shaft, a bearing positioned in each of said collars, with the bearings providing a means for maintaining a body in concentric relation with said central shaft.

2. In a device of the class described, a pair of spaced-apart collars having counterbores formed therein, bearings positioned in the counterbores with the bearings forming a means for maintaining a body in concentricrelation to the collars, a shaft extending through and between the collars, means provided on said shaft adjustably spacing said collars with relation to each other, and means rigidly secured to one end of said shaft and transmitting rotary motion thereto.

3. In an arbor attachment for lathes having a revolvable face plate located thereon, a central shaft, a lever rigidly secured to one end of said shaft and engaging the lathe face plate, a pair of collars slidably positioned on said shaft with a space formed between said collars for the reception of a differential case, means for rigidly clamping the differential case in fixed re lation with said shaft, and means for clamping the collars in fixed relation to the ends of the differential case.

4. In an arbor attachment for lathes, a central shaft, a pair of spaced-apart collars slidably positioned on said shaft, a counterbore formed in each side of each collar and providing for the reception of a bearing in either side of each of said collars.

5. In arbor attachments for lathes for finishing differential cases, the combination of an elongated central shaft, a lever rigidly secured to one end of said shaft with said lever being engaged by the face plate of the lathe, a pair of spaced-apart collars positioned on said shaft, a bearing positioned in each of said collars, and with said collars forming a space therebetween for the reception of a differential case, means for clamping the bearings against the end portions of the differential case, and means securing the differential case in fixed relation with the central shaft.

6. In an arbor attachment for machining differential cases, an assembly comprising in combination, a central shaft, a pair of collars slidably positioned on said shaft, a bearing positioned in each of the collars with each of the bearings providing a means for supporting an end of a difierential case and maintaining the same in concentric relation to the central shaft, and means rigidly secured on one end of the central shaft and transmitting rotary motion to the entire assembly. 7

HAROLD HENWOOD. 

